JP6574144B2 - Relay device and relay system - Google Patents

Description

  The present invention relates to a relay device and a relay system, for example, a relay system including a PBB (Provider Backbone Bridges) network and an EoE (Ethernet over Ethernet) network, and a relay device installed at the boundary between the PBB network and the EoE network.

  For example, Patent Document 1 discloses a switching hub that converts a PBB frame and an EoE frame. Specifically, the switching hub performs BVID (Backbone VLAN ID) or ISID (backbone Service Instance VLAN ID) included in the PBB frame and EID (Extended) included in the EoE frame via the internal VID (VLAN ID). ID) and SVID (Service provider VLAN ID).

JP 2011-120032 A

  For example, a MAC-in-MAC method is known as a technique for realizing wide area Ethernet (Ethernet is a registered trademark). The MAC-in-MAC method encapsulates a customer MAC (Media Access Control) frame with a carrier MAC frame to further expand the number of VLANs and switch (core switch) in a wide area network. This is a technique for reducing the number of MAC addresses learned in the above. As a MAC-in-MAC method, as shown in Patent Document 1, an EoE method and a PBB method based on IEEE 802.1ah are known.

  In addition, in the Ethernet network, a control frame for maintenance / management is transferred in addition to a normal user frame. As a typical example of maintenance and management, two relay apparatuses installed in the Ethernet network confirm the presence / absence of communication with the other party by communicating control frames with each other. As such a control frame for confirming communication, the EoE system defines a control frame called an ECP (EoE Control Protocol) frame.

  Here, for example, there is a case where it is desired to check the presence / absence of communication between a plurality of EoE networks connected across the PBB network. As a relay method of the ECP frame in this case, relay devices installed respectively at the boundaries between the plurality of EoE networks and the PBB network relay the ECP frame from the EoE network to the PBB network in the EoE format, and the PBB network It is conceivable to relay the ECP frame from the EoE network in the EoE format. In this case, the ECP frame is handled as a general VLAN frame in the PBB network.

  However, an ECP frame generated in the EoE network can have an identification space obtained by extending a 12-bit VLAN with an 8-bit EID (Extended ID), whereas an ECP frame in the PBB network has a 12-bit It is possible to provide only an identification space. As a result, the relay device that relays the ECP frame from the PBB network to the EoE network may be able to identify the ECP frame only in the 12-bit identification space. That is, if the frame from the PBB network is a PBB-format PBB frame, the relay apparatus can extend the 12-bit identification space using a method such as that disclosed in Patent Document 1. In the case of the EoE format ECP frame, EID cannot be recognized, and it may be difficult to expand the identification space. As a result, there is a risk that the practical ECP frame identification space is insufficient.

  The present invention has been made in view of the above, and one of its purposes is to provide a sufficient identification space when an ECP frame is communicated between a plurality of EoE networks connected across a PBB network. Is to provide a relay device and a relay system.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of a typical embodiment will be briefly described as follows.

  The relay device according to the present embodiment includes a PBB port connected to the PBB network, an EoE port connected to the EoE network, and a relay processing unit. When the frame received at the EoE port is an ECP frame, the relay processing unit generates an encapsulated ECP frame by encapsulating it with a PBB header, and relays it to the PBB port. Further, when the frame received at the PBB port is an encapsulated ECP frame, the relay processing unit generates an ECP frame by decapsulating the frame and relays it to the EoE port.

  The effects obtained by the representative embodiments of the invention disclosed in this application will be briefly described. When an ECP frame is communicated between a plurality of EoE networks connected across a PBB network, sufficient identification is performed. It becomes possible to provide a space.

In the relay system by Embodiment 1 of this invention, it is the schematic which shows the example of a whole structure, and the operation example at the time of a user frame relay. FIG. 2 is a block diagram illustrating a schematic configuration example of a main part of a gateway device in the relay system of FIG. 1. FIG. 3 is a block diagram illustrating a schematic configuration example of a main part of a PBB line card in the gateway device of FIG. 2. FIG. 3 is a block diagram illustrating a schematic configuration example of a main part of an EoE line card in the gateway device of FIG. 2. FIG. 5 is a schematic diagram illustrating an exemplary structure of the FDB in FIGS. 3 and 4. (A) is the schematic which shows the structural example of the VID conversion table in FIG. 3, (b) is the schematic which shows the structural example of the VID conversion table in FIG. 4, (c) is FIG. It is the schematic which shows the structural example of MC table in FIG. FIG. 5 is a schematic diagram illustrating a structure example of an intermediate frame generated by the relay processing unit in FIGS. 3 and 4. (A) is explanatory drawing which shows the schematic operation example at the time of relaying the user frame received with the port for EoE to the port for PBB in the gateway apparatus of FIG. 2, (b) is in the gateway apparatus of FIG. FIG. 4 is an explanatory diagram illustrating a schematic operation example when a user frame received at a PBB port is relayed to an EoE port. FIG. 3 is an explanatory diagram illustrating a schematic operation example when relaying an ECP frame in the relay system of FIG. 1. 2A is an explanatory diagram showing a schematic operation example when the ECP frame received at the EoE port is relayed to the PBB port in the gateway device of FIG. 2, and FIG. FIG. 5 is an explanatory diagram illustrating a schematic operation example when an ECP frame received at a PBB port is relayed to an EoE port. FIG. 5 is a flowchart illustrating an example of main processing contents of an EoE relay processing unit in the EoE line card of FIG. 4. It is explanatory drawing which shows an example of the problem at the time of relaying an ECP frame in the relay system used as the comparative example of this invention. It is a flowchart which shows an example of the main processing content of the relay processing part for EoE in the gateway apparatus by Embodiment 2 of this invention. It is explanatory drawing which shows an example of schematic operation | movement at the time of relaying an ECP frame in a relay system used as the comparative example of this invention, and an example of the problem in that case.

  In the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant, and one is the other. Some or all of the modifications, details, supplementary explanations, and the like are related. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
<< Schematic configuration of relay system >>
FIG. 1 is a schematic diagram showing an example of the overall configuration and an operation example during user frame relay in the relay system according to Embodiment 1 of the present invention. The relay system shown in FIG. 1 includes PB (Provider Bridges) networks 10a and 10b, EoE networks 11a and 11b, a PBB network 12, edge switch devices ESWe1 and ESWe2, and gateway devices (relay devices) GW1 and GW2. Have. The edge switch device ESWe1 is installed at the boundary between the PB network 10a and the EoE network 11a, and the edge switch device ESWe2 is installed at the boundary between the PB network 10b and the EoE network 11b. The gateway device GW1 is installed at the boundary between the EoE network 11a and the PBB network 12, and the gateway device GW2 is installed at the boundary between the EoE network 11b and the PBB network 12.

  The PB networks 10a and 10b respectively transfer user frames in S-TAG format (referred to as S-TAG frames in this specification) UF1a and UF1b based on IEEE802.1ad. Each of the S-TAG frames UF1a and UF1b includes a destination MAC address DA, a source MAC address SA, an S-TAG, and a payload. The S-TAG includes a 12-bit SVID (Service provider VLAN ID). Including.

  The EoE networks 11a and 11b transfer EoE-format user frames (referred to as EoE frames in this specification) UF2a and UF2b, respectively. Each of the EoE frames UF2a and UF2b has a structure in which the S-TAG frames UF1a and UF1b (specifically, the destination MAC address DA, the source MAC address SA and the payload therein) are encapsulated by the EoE header 15. The EoE header 15 includes a destination MAC address (in other words, an encapsulation address) EDA, a transmission source MAC address (encapsulation address) ESA, an S-TAG, and an E-TAG.

  The S-TAG of the EoE header 15 has the same content as the S-TAG included in the S-TAG frames UF1a and UF1b, for example. The E-TAG includes a type identifier TPID and an EID (Extended ID). The type identifier TPID represents the type of frame such as an EoE format user frame or an EoE format control frame (that is, an ECP frame), and is set to “0xE0E0” in the case of an EoE format user frame. The EID is an 8-bit identifier that extends the 12-bit SVID in the S-TAG. As a result, each of the EoE frames UF2a and UF2b has a 20-bit identification space.

  The PBB network 12 transfers a user frame (referred to as a PBB frame in this specification) UF3 in the PBB format. Similar to the EoE frame, the PBB frame UF3 has a structure in which the S-TAG frames UF1a and UF1b (specifically, the destination MAC address DA, the source MAC address SA and the payload therein) are encapsulated by the PBB header 16. . The PBB header 16 includes a destination MAC address (in other words, an encapsulation address) BDA, a transmission source MAC address (encapsulation address) BSA, a B-TAG, and an I-TAG.

  The B-TAG includes a 12-bit BVID (Backbone VLAN ID). BVID is an identifier that defines a frame transfer path within the PBB network 12. A switch device (core switch) (not shown) in the PBB network 12 relays a frame based on the BVID. The I-TAG includes a type identifier TPID representing a frame type and a 24-bit ISID (backbone Service Instance VLAN ID). The type identifier TPID is set to a predetermined value indicating that the frame includes an I-TAG. The ISID is an identifier that includes, for example, the SVID included in the S-TAG frames UF1a and UF1b and extends the SVID. As a result, the PBB frame UF3 has a 24-bit identification space.

<< User frame relay operation of relay system >>
Next, a schematic operation of the relay system will be described assuming that the S-TAG frame UF1a from the PB network 10a is transferred toward the PB network 10b. The edge switch device ESWe1 generates the EoE frame UF2a by encapsulating the S-TAG frame UF1a with the EoE header 15. At this time, the edge switch device ESWe1 determines the source MAC address ESA of the EoE header 15 as its own MAC address 'MA1', and sets the destination MAC address EDA based on the search result of FDB (Forwarding DataBase). Set to the MAC address 'MA2' of ESWe2.

  The gateway device GW1 generates a PBB frame UF3 by converting the EoE header 15 included in the EoE frame UF2a into a PBB header 16. At this time, the destination MAC address EDA and the source MAC address ESA of the EoE header 15 are taken over by the destination MAC address BDA and the source MAC address BSA of the PBB header 16, respectively.

  The gateway device GW2 generates the EoE frame UF2b by converting the PBB header 16 included in the PBB frame UF3 into the EoE header 15. At this time, the destination MAC address BDA and the source MAC address BSA of the PBB header 16 are succeeded to the destination MAC address EDA and the source MAC address ESA of the EoE header 15, respectively. Although not necessarily limited, the EoE frame UF2b has the same content as the EoE frame UF2a.

  Since the destination MAC address EDA of the received EoE frame UF2b is the MAC address “MA2” of the own device, the edge switch device ESWe2 generates the S-TAG frame UF1b by decapsulating the EoE frame UF2b. Specifically, the edge switch device ESWe2 generates the S-TAG frame UF1b by removing the EoE header 15 from the EoE frame UF2b and adding the S-TAG. Although not necessarily limited, the S-TAG frame UF1b has the same content as the S-TAG frame UF1a.

<< Schematic configuration of gateway device and user frame relay operation >>
FIG. 2 is a block diagram illustrating a schematic configuration example of a main part of the gateway device in the relay system of FIG. The gateway device (relay device) GW illustrated in FIG. 2 is, for example, a chassis type switch device that also has a function as an Ethernet switch. The gateway device GW includes a PBB line card LCp, an EoE line card LCe, and a frame relay path 20. For example, taking the gateway apparatus GW2 of FIG. 1 as an example, the PBB line card LCp includes a PBB port Pp1 connected to the PBB network 12 and an internal port Pi1 connected to the frame relay path 20. The EoE line card LCe includes an EoE port Pe1 connected to the EoE network 11b and an internal port Pi2 connected to the frame relay path 20.

  Here, the gateway apparatus GW includes one PBB line card LCp and one EoE line card LCe. However, the gateway apparatus GW may include a plurality of either one or both. Each of the PBB line card LCp and the EoE line card LCe includes one external port (that is, the PBB port Pp1 and the EoE port Pe1), but may include a plurality of external ports. The frame relay path 20 is responsible for relaying frames between the line cards. For example, the frame relay path 20 may be configured by a mesh communication line or a fabric switch.

  FIG. 3 is a block diagram showing a schematic configuration example of a main part of the PBB line card in the gateway device of FIG. FIG. 4 is a block diagram illustrating a schematic configuration example of a main part of the EoE line card in the gateway device of FIG. FIG. 5 is a schematic diagram illustrating an example of the structure of the FDB in FIGS. 3 and 4. 6A is a schematic diagram illustrating an example of the structure of the VID conversion table in FIG. 3, and FIG. 6B is a schematic diagram illustrating an example of the structure of the VID conversion table in FIG. ) Is a schematic diagram showing an example of the structure of the MC table in FIGS. 3 and 4. FIG. 7 is a schematic diagram showing an example of the structure of an intermediate frame generated by the relay processing unit shown in FIGS.

  The PBB line card LCp shown in FIG. 3 includes a PBB relay processing unit 25a and a multicast (abbreviated as MC) processing unit 26a in addition to the PBB port Pp1 and the internal port Pi1. The PBB relay processing unit 25a includes an FDB (Forwarding DataBase), an FDB processing unit 27a, a VID conversion table 28a, a PBB frame conversion unit 29a, and a PBB control frame processing unit 30a. The MC processing unit 26a includes an MC table 31a.

  Similarly, the EoE line card LCe shown in FIG. 4 includes an EoE relay processing unit 25b and an MC processing unit 26b in addition to the EoE port Pe1 and the internal port Pi2. The EoE relay processing unit 25b includes an FDB, an FDB processing unit 27b, a VID conversion table 28b, an EoE frame conversion unit 29b, and an EoE control frame processing unit 30b. The MC processing unit 26b includes an MC table 31b.

  FIG. 8A is an explanatory diagram showing a schematic operation example when the user frame received at the EoE port is relayed to the PBB port in the gateway device of FIG. 2, and FIG. 5 is an explanatory diagram showing a schematic operation example when a user frame received at a PBB port is relayed to an EoE port in the gateway device of FIG. FIG. 8A shows an operation example of the gateway device GW1 in FIG. 1, and FIG. 8B shows an operation example of the gateway device GW2 in FIG.

  For example, in FIG. 8B, when the PBB relay processing unit 25a of the PBB line card LCp receives a frame at the PBB port Pp1, it mainly determines whether the frame is a user frame UF or a control frame CF. Then, VID conversion, FDB learning and search, and generation of an intermediate frame MF are performed (step S201). Here, if the PBB relay processing unit 25a determines that the received frame is a user frame (that is, a PBB frame) UF3, the PBB frame is converted into an intermediate frame MF, and then the internal processing is performed via the MC processing unit 26a. Transmit to port Pi1.

  At this time, when the destination port of the frame has already been determined based on the FDB search result in step S201 (that is, in the case of a unicast frame), the MC processing unit 26a uses the intermediate frame MF as it is as the internal port Pi1. Send to. On the other hand, when the destination port of the frame is not determined (specifically, when there is a multicast flag described later), the MC processing unit 26a determines the destination port and then transmits the intermediate frame MF to the internal port Pi1. (Step S202).

  The frame relay path 20 relays the intermediate frame MF from the internal port Pi1 to the EoE line card LCe based on the destination port (here, the EoE port Pe1) (step S203). The EoE relay processing unit 25b of the EoE line card LCe receives the intermediate frame MF at the internal port Pi2, and if the frame is the user frame UF, the apparatus header (details will be described later) of the intermediate frame MF. The EoE frame UF2b is generated by converting into the EoE header 15 (step S204). Then, the EoE relay processing unit 25b relays the EoE frame UF2b to the EoE port Pe1 serving as a destination port.

  On the other hand, in FIG. 8A, processing is performed in which the processing contents of the PBB line card LCp and the EoE line card LCe in FIG. 8B are interchanged. That is, the EoE relay processing unit 25b and the MC processing unit 26b of the EoE line card LCe perform the same processing as Steps S201 and S202 of FIG. 8B in Steps S101 and S102, and the PBB of the PBB line card LCp. The relay processing unit 25a performs the same process as step S204 of FIG. 8B in step S104. Hereinafter, the details of FIGS. 3 and 4 will be described by taking the case of FIG. 8B as an example.

  In step S201 in FIG. 8B, the PBB relay processing unit 25a in FIG. 3 refers to the type identifier TPID or the like in the PBB header 16 of the received frame, for example, to determine whether it is the user frame UF or the control frame CF. It is determined whether it is. When the PBB relay processing unit 25a determines that the user frame (that is, PBB frame) UF3, the PBB relay processing unit 25a performs VID conversion using the VID conversion table 28a.

  As shown in FIG. 6A, the VID conversion table 28a holds a correspondence relationship between a preset internal VLAN identifier IVID, BVID, and ISID. The PBB relay processing unit 25a obtains the internal VLAN identifier IVID (here, “IV1”) corresponding to the BVID (here “BV1”) and the ISID (“IS1”) of the received PBB frame UF3, thereby performing the VID conversion. I do.

  In addition, the FDB processing unit 27a performs FDB learning and search. As shown in FIG. 5, the FDB holds a correspondence relationship between the MAC address, the internal VLAN identifier IVID, and the port identifier. In FIG. 5, for example, {Pp1} represents the identifier of the PBB port Pp1, and similarly, in this specification, {AA} represents the identifier of “AA”. In the example of FIG. 5, the MAC address ‘MA1’ is assigned ‘IV1’ as the internal VLAN identifier IVID, and exists ahead of the PBB port Pp1. The MAC address ‘MA2’ is assigned ‘IV1’ as the internal VLAN identifier IVID and exists at the end of the EoE port Pe1.

  The FDB processing unit 27a associates “MA1”, which is the transmission source MAC address BSA of the PBB frame UF3, with the acquired internal VLAN identifier IVID “IV1” and the reception port identifier (here, {Pp1}) of the frame. To learn to FDB. Further, the FDB processing unit 27a searches the FDB using 'MA2', which is the destination MAC address BDA of the frame, and the acquired internal VLAN identifier IVID'IV1 'as a search key, and a port identifier (referred to as a destination port identifier). To get. In the example of FIG. 5, the destination port identifier {Pe1} is acquired.

  Using these pieces of information, the PBB relay processing unit 25a generates an intermediate frame MF. . As shown in FIG. 7, the intermediate frame MF has a structure in which the PBB header 16 included in the PBB frame UF <b> 3 is replaced with an in-device header 35. The in-device header 35 includes a destination MAC address BEDA and a source MAC address BESA that are an encapsulation address (6 bytes), a frame type FTYP, a destination port identifier DPID, a reception port identifier SPID, and an internal VLAN identifier IVID. And a multicast flag MCFLG.

Here, the destination MAC address BEDA is “MA2” which is the same as the destination MAC address BDA, and the source MAC address BESA is “MA1” which is the same as the source MAC address BSA. The frame type FTYP is a predetermined identifier representing the result of the above-described frame type determination (here, a user frame). The destination port identifier DPID is {Pe1}, the reception port identifier SPID is {Pp1}, and the internal VLAN identifier IVID is “IV1”. The multicast flag MCFLG is flagged when the FDB search result is a miss hit. Specifically, for example, when the destination MAC address BDA is not learned in the FDB or is a multicast or broadcast address, the FDB processing unit 27a sets the multicast flag MCFLG as flagged.

  When the PBB relay processing unit 25a receives a frame at the PBB port Pp1 and the frame is a user frame UF, the PBB frame conversion unit 29a or the PBB control frame processing unit 30a does not pass through the processing. The intermediate frame MF is transmitted to the MC processing unit 26a. Note that the PBB control frame processing unit 30a performs predetermined processing, for example, when the received frame is a PBB control frame. The control frame for PBB is, for example, ITU-T Y. 1731 and a frame based on Ethernet OAM specified by IEEE802.1ag. The PBB frame conversion unit 29a converts the intermediate frame MF into a PBB frame when the intermediate frame MF is received at the internal port Pi1 as in step S104 of FIG. 8A and the frame is a user frame. .

  In step S202 of FIG. 8B, the MC processing unit 26a receives the intermediate frame MF from the PBB relay processing unit 25a, and if the multicast flag MCFLG has no flag (that is, a unicast frame), The intermediate frame MF is transmitted to the internal port Pi1. On the other hand, when the multicast flag MCFLG has a flag, the MC processing unit 26a determines the destination port based on the MC table 31a, and then transmits the intermediate frame MF to the internal port Pi1.

  In the MC table 31a, as shown in FIG. 6C, the correspondence relationship between the internal VLAN identifier IVID and the port identifier is held. The MC processing unit 26a acquires one or more port identifiers corresponding to the internal VLAN identifier IVID included in the intermediate frame MF based on the MC table 31a, and sets each port identifier excluding the reception port from the inside of the device. The destination port identifier DPID of the header 35 is used.

  In step S203 of FIG. 8B, the frame relay path 20 uses the intermediate frame MF from the internal port Pi1 as a line card (here, EoE line card LCe) based on the destination port identifier DPID (here, {Pe1}). Relay to. In step S204 of FIG. 8B, the EoE frame conversion unit 29b of the EoE relay processing unit 25b converts the in-device header 35 of the intermediate frame MF received at the internal port Pi2 into the EoE header 15 based on the VID conversion table 28b. An EoE frame is generated by conversion.

  As shown in FIG. 6B, the VID conversion table 28b holds a correspondence relationship between the preset internal VLAN identifier IVID, SVID, and EID. The EoE frame conversion unit 29b acquires SVID 'SV1' and EID 'EI1' corresponding to the internal VLAN identifier IVID 'IV1' of the intermediate frame MF based on the VID conversion table 28b. Then, using these pieces of information, the EoE frame conversion unit 29b performs header conversion for converting the in-device header 35 into the EoE header 15 of the EoE frame UF2b in FIG.

  Specifically, the destination MAC address EDA and the source MAC address ESA of the EoE header 15 are determined as the destination MAC address BEDA 'MA2' and the source MAC address BESA 'MA1' of the in-device header 35, respectively. Further, the SVID and EID of the EoE header 15 are set to values (here, “SV1” and “EI1”) acquired based on the VID conversion table 28b. The EoE relay processing unit 25b transmits the EoE frame UF2b generated in this way to the EoE network 11b via the EoE port Pe1 indicated by the destination port identifier DPID of the intermediate frame MF.

  Similarly to FIG. 8B, in the case of FIG. 8A, the EoE relay processing unit 25b converts the SVID and EID into the internal VLAN identifier IVID based on the VID conversion table 28b in step S101. An intermediate frame MF is generated by performing conversion or the like. In step S104, the PBB frame conversion unit 29a of the PBB relay processing unit 25a performs header conversion for converting the internal VLAN identifier IVID of the in-device header 35 into the BVID and ISID of the PBB header 16 based on the VID conversion table 28a. By doing so, a PBB frame is generated.

  As described above, the gateway device (relay device) GW of FIG. 2 generally has a mechanism for mutually converting BVID and ISID, SVID and EID through the internal VLAN identifier IVID. Accordingly, when the frame received at the EoE port Pe1 is a user frame (EoE frame), the gateway device GW generates the PBB frame by converting the EoE header 15 included in the frame into the PBB header 16. Can do. Similarly, when the frame received at the PBB port Pp1 is a user frame (PBB frame), the gateway device GW generates an EoE frame by converting the PBB header 16 included in the frame into the EoE header 15. Can do.

  3 and 4, each of the PBB relay processing unit 25a and the EoE relay processing unit 25b is connected to, for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), a CAM (Content Addressable Memory). ), RAM (Random Access Memory), ROM (Read Only Memory), and the like. Specifically, the FDB is mounted on the CAM, the VID conversion tables 28a and 28b are mounted on the RAM and the ROM, and the other processing units are mounted on the FPGA. However, a part of the PBB frame conversion unit 29a and the PBB control frame processing unit 30a and a part of the EoE frame conversion unit 29b and the EoE control frame processing unit 30b may be implemented by program processing using a CPU. .

  In addition, each of the MC processing units 26a and 26b is configured, for example, by combining an ASIC or FPGA with a RAM and a ROM. Each of the MC tables 31a and 31b is mounted on a RAM, a ROM, or the like. However, the specific mounting form of each part is of course not limited to these, and may be appropriately mounted using hardware, software, or a combination thereof.

<< Problems at ECP Frame Relay in Relay System (Comparative Example [1]) >>
FIG. 14 is an explanatory diagram showing an example of a schematic operation when relaying an ECP frame and an example of a problem at that time in a relay system as a comparative example of the present invention. In FIG. 14, the edge switch device ESWe1 of the EoE network 11a transmits an ECP frame CF1a serving as a control frame to the edge switch device ESWe2 of the EoE network 11b via the PBB network 12. The ECP frame CF1a has a structure in which an EoE header 15a similar to the case of FIG. 1 is added to a payload in which various control information and the like are stored.

  In the EoE header 15a, the destination MAC address EDA is 'MA2', and the source MAC address ESA is 'MA1'. The type identifier TPID is '0xE0EC' unlike the case of the user frame (EoE frame) in FIG. For example, SVID and EID are set to values dedicated to control frames that do not overlap with user frames.

  Here, the gateway apparatus GW1 'can relay the ECP frame CF1a from the EoE network 11a to the PBB network 12 in the frame format using the EoE header 15a (ie, EoE format). In this case, the ECP frame CF1a is regarded as a general VLAN tag frame in the PBB network 12, and a core switch (not shown) in the PBB network 12 uses a 12-bit SVID instead of the 12-bit BVID shown in FIG. The relay route can be determined based on The gateway device GW2 'can also relay the ECP frame CF1a from the PBB network 12 to the EoE network 11b in the EoE format.

  However, when such a method is used, the gateway device GW2 ′ receives the ECP frame CF1a using the EoE header 15a instead of the PBB header 16 in the case of FIG. 1 at the PBB port Pp1. . In this case, the gateway device GW2 'can recognize the 12-bit SVID included in the EoE header 15a as a BVID, but cannot recognize the 8-bit EID. As a result, the gateway device GW2 ′ needs to determine the internal VLAN identifier IVID based on the 12-bit SVID (BVID) at the time of VID conversion as described above, and the identification space of the practical ECP frame CF1a is 12 bits. It will be limited to.

  In reality, the EoE networks 11a and 11b are provided with many edge switch devices, and there is a case where it is desired to confirm the mutual communication between the edge switch devices while distinguishing the VLAN values in various ways. . However, in practice, most of the VLAN values are used in user frames, so it may be difficult to satisfy such requirements with the remaining values. That is, with 12 bits, there is a risk that the practical ECP frame identification space is insufficient.

<< Relay Operation of ECP Frame in Relay System (Embodiment 1) >>
FIG. 9 is an explanatory diagram showing a schematic operation example when relaying an ECP frame in the relay system of FIG. In FIG. 9, unlike the case of FIG. 14, the gateway device (relay device) GW1 receives the ECP frame CF1a from the EoE port Pe1 via the EoE network 11a, and converts the ECP frame CF1a into the PBB header 16. The encapsulated ECP frame CF2 is generated by encapsulating with. At this time, the gateway device GW1 determines whether the frame is an ECP frame by referring to the type identifier TPID of the E-TAG.

  For example, the gateway apparatus GW1 determines the destination MAC address BDA and the source MAC address BSA of the PBB header 16 in the encapsulated ECP frame CF2 as the destination MAC address EDA and the source MAC address ESA of the EoE header 15a, respectively. Further, the gateway device GW1 determines the BVID and ISID of the PBB header 16 in the same manner as in the case of the user frame described above. That is, the gateway device GW1 converts the SVID and EID of the EoE header 15a into BVID and ISID via the internal VLAN identifier IVID.

  Further, the gateway apparatus GW1 also leaves the E-TAG in the encapsulated ECP frame CF2 in addition to the destination MAC address EDA, the source MAC address ESA and the payload included in the ECP frame CF1a before being encapsulated. Then, the gateway device GW1 relays the encapsulated ECP frame CF2 generated in this way to the PBB port Pp1 (PBB network 12).

  On the other hand, unlike the case of FIG. 14, the gateway device (relay device) GW2 decapsulates the encapsulated ECP frame CF2 when the frame received at the PBB port Pp1 via the PBB network 12 is the encapsulated ECP frame CF2. To generate an ECP frame CF1b. At this time, the gateway device GW2 determines whether or not the frame is an ECP frame by referring to the E-TAG type identifier TPID remaining in the encapsulated ECP frame CF2.

  Further, the gateway device GW2 determines the SVID and EID of the EoE header 15a in the same manner as in the case of the user frame described above. That is, the gateway device GW2 converts the BVID and ISID of the PBB header 16 into SVID and EID via the internal VLAN identifier IVID. Further, the gateway apparatus GW2 sets the E-TAG type identifier TPID in the EoE header 15a to “0xE0EC” representing the ECP frame. As a result, the ECP frame CF1b is a frame having the same content as the ECP frame CF1a, although not necessarily limited thereto. Then, the gateway device GW2 relays the ECP frame CF1b to the EoE port Pe1 (EoE network 11b).

  When the above method is used, the gateway device GW2 can receive the ECP frame encapsulated by the PBB header 16 (that is, the encapsulated ECP frame CF2) at the PBB port Pp1. For this reason, the gateway device GW2 can provide a recognition space exceeding 12 bits for the ECP frame as in the case of the user frame. For example, a maximum 20-bit identification space consisting of SVID and EID can be provided, and when the number of bits of the internal VLAN identifier IVID is more than 12 bits and less than 20 bits (for example, 15 bits). , An identification space having the number of bits can be provided. As a result, compared to the case of FIG. 14, it is possible to provide a sufficient identification space for the ECP frame.

  FIG. 10A is an explanatory diagram showing a schematic operation example when the ECP frame received at the EoE port is relayed to the PBB port in the gateway device of FIG. 2, and FIG. 5 is an explanatory diagram showing a schematic operation example when relaying an ECP frame received at a PBB port to an EoE port in the gateway device of FIG. 10A shows an operation example of the gateway device GW1 in FIG. 9, and FIG. 10B shows an operation example of the gateway device GW2 in FIG.

  In FIG. 10A, when the EoE relay processing unit 25b of the EoE line card LCe receives a frame at the EoE port Pe1, as in FIG. 8A, mainly the received frame Type determination, VID conversion, FDB learning and search, and generation of an intermediate frame MF are performed (step S301). In step S301, the EoE relay processing unit 25b determines that the received frame is a control frame (ie, an ECP frame) CF1a.

  In this case, the EoE relay processing unit 25b converts the SVID and EID of the ECP frame CF1a into the internal VLAN identifier IVID based on the VID conversion table 28b of FIG. 6B, similarly to the case of FIG. The FDB is learned and searched using the internal VLAN identifier IVID. Then, the EoE relay processing unit 25b generates the intermediate frame MF by a method different from that in the case of FIG.

  Specifically, in the case of FIG. 8A, the EoE relay processing unit 25b generates an intermediate frame MF in which the EoE header 15 of the user frame is replaced with the in-device header 35. In the case of a), an intermediate frame MF in which the in-device header 35 is added to the ECP frame CF1a is generated. In other words, the EoE relay processing unit 25b generates the intermediate frame MF by encapsulating the ECP frame CF1a with the in-device header 35.

  At the time of this encapsulation, the EoE relay processing unit 25b, for example, uses the destination MAC address BEDA and the source MAC address BESA of the in-device header 35 as the destination MAC address EDA and the source MAC address ESA of the ECP frame CF1a, respectively. Stipulated in Further, the EoE relay processing unit 25b determines the frame type FTYP of the in-device header 35 as a predetermined identifier representing an ECP frame. Further, the EoE relay processing unit 25b determines the multicast flag MCFLG, the internal VLAN identifier IVID, the reception port identifier SPID, and the destination port identifier DPID of the in-device header 35 in the same manner as in the above-described user frame.

  Thereafter, in steps S302 and S303 in FIG. 10A, the same processing as in steps S102 and S103 in FIG. 8A is performed, and then the PBB line card LCp receives the intermediate frame MF at the internal port Pi1. In this case, in step S304, the PBB relay processing unit 25a converts the in-device header 35 of the intermediate frame MF into the PBB header 16 in the same manner as in step S104 of FIG. The encapsulated ECP frame CF2 shown is generated.

  On the other hand, in FIG. 10B, when the PBB relay processing unit 25a of the PBB line card LCp receives a frame at the PBB port Pp1, it receives mainly as in FIG. 8B. Frame type determination, VID conversion, FDB learning and search, and generation of an intermediate frame MF are performed (step S401). In step S401, the PBB relay processing unit 25a determines that the received frame is a control frame (that is, an encapsulated ECP frame) CF2.

  In this case, the PBB relay processing unit 25a converts the BVID and ISID of the encapsulated ECP frame CF2 into the internal VLAN identifier IVID based on the VID conversion table 28a of FIG. 6A, as in the case of FIG. 8B. Conversion is performed, and FDB learning and retrieval are performed using the internal VLAN identifier IVID. The PBB relay processing unit 25a generates the intermediate frame MF in the same manner as in the case of FIG. However, at this time, the PBB relay processing unit 25a determines the frame type FTYP of the in-device header 35 as a predetermined identifier representing an ECP frame.

  Thereafter, in steps S402 and S403 in FIG. 10B, the same processing as in steps S202 and S203 in FIG. 8B is performed, and then the EoE line card LCe receives the intermediate frame MF at the internal port Pi2. The EoE relay processing unit 25b recognizes that the intermediate frame MF is an ECP frame based on the frame type FTYP of the in-device header 35. In this case, the EoE relay processing unit 25b converts the intermediate frame MF in step S404 by a method different from that in step S204 of FIG.

  Specifically, in the case of FIG. 8B, the EoE relay processing unit 25b generates the EoE frame by converting the in-device header 35 of the intermediate frame MF into the EoE header 15, but FIG. In the case of a), the in-device header 35 is deleted from the intermediate frame MF, and the S-TAG and E-TAG are added to generate the ECP frame CF1b shown in FIG. In other words, the EoE relay processing unit 25b generates the ECP frame CF1b by decapsulating the intermediate frame MF. At this time, the EoE relay processing unit 25b determines SVID and EID based on the VID conversion table 28b of FIG. 6B, as in the case of the user frame.

<< Processing content of relay processing unit for EoE >>
FIG. 11 is a flowchart showing an example of main processing contents of the EoE relay processing unit in the EoE line card of FIG. In FIG. 11, the EoE relay processing unit 25b determines whether or not a frame has been received (step S501), and if received, determines whether or not the frame is an ECP frame (step S502). . Specifically, when the EoE relay processing unit 25b receives a frame at the EoE port Pe1 as in FIG. 10A, the EoE relay processing unit 25b refers to the type identifier TPID included in the EoE header 15a. When the frame is received at the internal port Pi2 as in the case of 10 (b), the frame type FTYP included in the in-device header 35 is referred to.

  If the determination result in step S502 is an ECP frame, the EoE relay processing unit 25b changes the processing depending on whether the frame is received at the external port (that is, the EoE port Pe1) or the internal port Pi2. . When received by the external port, the EoE relay processing unit 25b performs VID conversion and FDB learning and search (step S301a) as shown in step S301 of FIG. A frame MF is generated (step S301b) and relayed to the destination port (step S301c). The encapsulation processing in step S301b is performed by the EoE control frame processing unit 30b of the EoE relay processing unit 25b in FIG.

  On the other hand, when received by the internal port Pi2, the EoE relay processing unit 25b generates an ECP frame by decapsulation as shown in step S404 of FIG. 10B (step S404a), and sends it to the destination port ( That is, it relays to the EoE port Pe1) (step S404b). The decapsulation process in step S404a is performed by the EoE control frame processing unit 30b of the EoE relay processing unit 25b in FIG.

  If the determination result in step S502 is not an ECP frame (that is, a user frame (EoE frame)), the EoE relay processing unit 25b has received the frame at an external port (that is, an EoE port Pe1), or an internal The processing is changed depending on whether the message is received at the port Pi2. When received at the external port, the EoE relay processing unit 25b performs VID conversion and FDB learning and search (step S101a) as shown in step S101 of FIG. An intermediate frame MF is generated by header conversion (step S101b) and relayed to the destination port (step S101c).

  On the other hand, when received by the internal port Pi2, the EoE relay processing unit 25b generates an EoE frame by header conversion instead of decapsulation as shown in step S204 of FIG. 8B (step S204a). Is relayed to the destination port (that is, EoE port Pe1) (step S204b). The header conversion process in step S204a is performed by the EoE frame conversion unit 29b of the EoE relay processing unit 25b in FIG.

  As described above, by using the relay device and the relay system according to the first embodiment, typically, when an ECP frame is communicated between a plurality of EoE networks connected across the PBB network, a sufficient identification space is provided. It becomes possible to provide. Further, when relaying ECP frames, VID conversion performed when relaying user frames can be used as it is, so that the apparatus configuration and processing efficiency can be improved.

(Embodiment 2)
<< Problems at ECP Frame Relay in Relay System (Comparative Example [2]) >>
FIG. 12 is an explanatory diagram showing an example of a problem in relaying an ECP frame in a relay system as a comparative example of the present invention. The relay system shown in FIG. 12 includes the PB network 10c in addition to the EoE networks 11a and 11b, the PBB network 12, the edge switch devices ESWe1 and ESWe2 and the gateway devices (relay devices) GW1 and GW2 shown in FIG. Edge switch devices ESWe3 and ESWp1 are provided.

  As with the edge switch device ESWe1, the edge switch device ESWe3 is installed at the boundary between the EoE network 11a and a PB network (not shown). The edge switch device ESWp1 is installed at the boundary between the PB network 10c and the PBB network 12, and is responsible for conversion between the S-TAG frame and the PBB frame as shown in FIG. Each of gateway apparatuses GW1 and GW2 relays an ECP frame using the method described in the first embodiment.

  Here, in the example of FIG. 12, the edge switch device ESWe1 for EoE uses the ECP for the edge switch devices ESWe2 and ESWe3 that are also used for EoE and the gateway devices GW1 and GW2 corresponding to EoE. Communication is confirmed using the frame CF1a. For this reason, the destination MAC address EDA of the ECP frame CF1a is determined as a multicast (MC) address. As a result, when the method of the first embodiment is used, the destination MAC address BDA of the encapsulated ECP frame CF2 from the gateway device GW1 is the MC address, and the source MAC address BSA is 'MA1'.

  However, two problems can arise in this case. The first problem is that the PBB edge switch device ESWp1 receives the encapsulated ECP frame CF2 whose destination MAC address BDA is the MC address. In this case, the PBB edge switch device ESWp1 includes its own device in the destination MAC address BDA, and therefore performs decapsulation and floods the decapsulated frame to the PB network 10c. As a result, in the PB network 10c, ECP frames that are originally unnecessary are transferred, and there is a possibility that the communication band of the PB network 10c is unnecessarily compressed.

  The second problem is that the edge switch device ESWp1 for PBB receives the encapsulated ECP frame CF2 in which the source MAC address ESA before encapsulation and the source MAC address BSA of the PBB header are both “MA1”. There is in point to do. In this case, the edge switch device ESWp1 for PBB learns the FDB of its own device by associating “MA1” as the source MAC address ESA with “MA1” as the source MAC address BSA. Since the FDB entry is an essentially unnecessary entry, the FDB entry may be consumed wastefully.

<< Processing content of relay processing unit for EoE (application example) >>
FIG. 13 is a flowchart showing an example of main processing contents of the EoE relay processing unit in the gateway device according to the second embodiment of the present invention. The flow shown in FIG. 13 is a flow obtained by extracting the processes of steps S501 to S503 and step S301 from the flow of FIG. 11 described above. However, the processing content of step S301 differs between FIG. 13 and FIG.

  In step S301 in FIG. 13, steps S301d, S301e, and S301f are added between steps S301b and S301c. In step S301d, for example, the EoE relay processing unit 25b (specifically, the EoE control frame processing unit 30b) of the gateway device GW1 of FIG. 12 receives the destination MAC address EDA of the ECP frame CF1a received at the EoE port Pe1. Is a multicast address. In the determination, specifically, the EoE control frame processing unit 30b refers to an I / G bit indicating whether or not the destination MAC address EDA is multicast.

  When the destination MAC address EDA is a multicast address in step S301d, the EoE control frame processing unit 30b determines the destination MAC address BEDA of the intermediate frame MF as a MAC address that is a specified unknown unicast (step S301e). As a result, the EoE control frame processing unit 30b determines the destination MAC address BDA of the PBB header 16 of the encapsulated ECP frame CF2 as a MAC address that is an unknown unicast.

  The MAC address used as the unknown unicast is an unused address in the EoE networks 11a and 11b and the PBB network 12 installed in the relay system, for example, and is an address set in advance by the user. When the destination MAC address EDA of the ECP frame CF1a received at the EoE port Pe1 is a multicast address, as described above, one or a plurality of destination ports are determined by the MC processing unit 26b of FIG.

  After the process of step S301e, the EoE control frame processing unit 30b executes the process of step S301f. Further, when the destination MAC address EDA is a unicast address in step S301d, the EoE control frame processing unit 30b executes the process of step S301f without performing the process of step S301e. In step S301f, the EoE control frame processing unit 30b determines the source MAC address BESA of the intermediate frame MF as a broadcast address or a multicast address. As a result, the EoE control frame processing unit 30b determines the source MAC address BSA of the PBB header 16 of the encapsulated ECP frame CF2 as a broadcast address or a multicast address.

  As described above, the first problem shown in FIG. 12 can be solved by the processing in step S301e. That is, when the destination MAC address BDA of the received encapsulated ECP frame CF2 is unknown unicast, the edge switch device ESWp1 for PBB floods only the PBB network 12 without decapsulating the frame. Further, the second problem shown in FIG. 12 can be solved by the processing in step S301f. That is, the edge switch apparatus ESWp1 for PBB does not perform FDB learning when the transmission source MAC address BSA of the received encapsulated ECP frame CF2 is a broadcast address or a multicast address.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. . Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  For example, in FIG. 2, a chassis-type gateway device is taken as an example, but a box-type gateway device may of course be used. In this case, for example, the PBB relay processing unit 25a in FIG. 3 and the EoE relay processing unit 25b in FIG. 4 are configured as one relay processing unit, and the MC processing unit 26a in FIG. 3 and the MC processing unit in FIG. 26b may be configured as one MC processing unit.

10a, 10b, 10c PB network 11a, 11b EoE network 12 PBB network UF1a, UF1b User frame (S-TAG frame)
UF2a, UF2b User frame (EoE frame)
UF3 PBB frame 15, 15a EoE header 16 PBB header Pp1 PBB port LCp PBB line card LCe EoE line card Pe1 EoE port GW, GW1, GW2 Gateway device (relay device)
ESWe1, ESWe2, ESWe3, ESWp1 Edge switch device 20 Frame relay path Pi1, Pi2 Internal port 25a PBB relay processing unit 26a, 26b MC processing unit 27a, 27b FDB processing unit 28a, 28b VID conversion table 29a PBB frame conversion unit 30a PBB Control frame processing unit 31a, 31b MC table 29b EoE frame conversion unit 30b EoE control frame processing unit 35 In-device header MF Intermediate frame CF1a, CF1b Control frame (ECP frame)
CF2 encapsulated ECP frame

Claims (10)

A PBB port connected to a PBB (Provider Backbone Bridge) network;
An EoE port connected to an EoE (Ethernet over Ethernet) network;
When the frame received at the EoE port via the EoE network is an ECP (EoE Control Protocol) frame, the ECP frame is encapsulated with a PBB header to generate an encapsulated ECP frame, and the encapsulated ECP The frame is relayed to the PBB port, and if the frame received at the PBB port via the PBB network is the encapsulated ECP frame, the ECP frame is generated by decapsulating the encapsulated ECP frame. A relay processing unit that relays the ECP frame to the EoE port;
A relay device. The relay device according to claim 1,
When the destination MAC address of the ECP frame received at the EoE port is a multicast address, the relay processing unit changes the destination MAC address of the PBB header of the encapsulated ECP frame to a MAC address that becomes unknown unicast. Define
Relay device. The relay device according to claim 1 or 2,
When the frame received at the EoE port is the ECP frame, the relay processing unit determines a transmission source MAC address of the PBB header of the encapsulated ECP frame as a broadcast address or a multicast address.
Relay device. The relay device according to claim 1,
When the frame received at the EoE port via the EoE network is a user frame, the relay processing unit generates a PBB frame by converting an EoE header of the user frame into a PBB header, and generates the PBB frame. When the frame received at the PBB port via the PBB network is a user frame, an EoE frame is generated by converting the PBB header of the user frame into an EoE header, Relay the EoE frame to the EoE port;
Relay device. The relay device according to claim 1 or 4,
The relay processing unit
During the encapsulation, SVID (Service provider VLAN ID) and EID (Extended ID) of the EoE header of the ECP frame are converted into BVID (Backbone VLAN ID) and ISID (backbone Service Instance VLAN ID) via the internal VLAN identifier. To determine the BVID and ISID of the PBB header of the encapsulated ECP frame,
In the decapsulation, the SVID and EID of the EoE header of the ECP frame are determined by converting the BVID and ISID included in the PBB header of the encapsulated ECP frame into SVID and EID via the internal VLAN identifier.
Relay device. Multiple EoE (Ethernet over Ethernet) networks,
PBB (Provider Backbone Bridge) network,
A plurality of relay devices respectively installed at boundaries between the plurality of EoE networks and the PBB network;
A relay system comprising:
Each of the plurality of relay devices is
A PBB port connected to the PBB network;
An EoE port connected to the EoE network;
When the frame received at the EoE port via the EoE network is an ECP (EoE Control Protocol) frame, the ECP frame is encapsulated with a PBB header to generate an encapsulated ECP frame, and the encapsulated ECP The frame is relayed to the PBB port, and if the frame received at the PBB port via the PBB network is the encapsulated ECP frame, the ECP frame is generated by decapsulating the encapsulated ECP frame. A relay processing unit that relays the ECP frame to the EoE port;
A relay system. The relay system according to claim 6,
When the destination MAC address of the ECP frame received at the EoE port is a multicast address, the relay processing unit changes the destination MAC address of the PBB header of the encapsulated ECP frame to a MAC address that becomes unknown unicast. Define
Relay system. The relay system according to claim 6 or 7,
When the frame received at the EoE port is the ECP frame, the relay processing unit determines a transmission source MAC address of the PBB header of the encapsulated ECP frame as a broadcast address or a multicast address.
Relay system. The relay system according to claim 6,
When the frame received at the EoE port via the EoE network is a user frame, the relay processing unit generates a PBB frame by converting an EoE header included in the user frame into a PBB header, and When a PBB frame is relayed to the PBB port and the frame received at the PBB port via the PBB network is a user frame, an EoE frame is converted by converting a PBB header included in the user frame into an EoE header. And relay the EoE frame to the EoE port.
Relay system. The relay system according to claim 6 or 9,
The relay processing unit
During the encapsulation, SVID (Service provider VLAN ID) and EID (Extended ID) of the EoE header of the ECP frame are converted into BVID (Backbone VLAN ID) and ISID (backbone Service Instance VLAN ID) via the internal VLAN identifier. To determine the BVID and ISID of the PBB header of the encapsulated ECP frame,
In the decapsulation, the SVID and EID of the EoE header of the ECP frame are determined by converting the BVID and ISID included in the PBB header of the encapsulated ECP frame into SVID and EID via the internal VLAN identifier.
Relay system.

Images